Sure, there are actually four contests taking place today -- in Alabama, Mississippi, Hawaii and American Samoa. But in terms of the ones to watch, it's all about the South. Here's what I'll be looking for as the results roll in tonight.

Can Romney Overcome His "Southern Problem"?

Nobody ever gives Mitt Romney credit for winning Florida and Virginia (especially when, in the latter case, he shared the ballot with just one other candidate, Ron Paul). Even with those states on his record, he's still at a disadvantage when it comes to winning over the South.

"Romney has less of an appeal to self-described conservatives, and the South, particularly the Deep South, is a more conservative part of the country," Vincent Hutchings, a professor at the University of Michigan's Center for Political Studies, told The Root. The region is also more working class, which poses another hurdle for Romney.

That said, he is still showing strength in Alabama and Mississippi, splitting voters almost evenly with his strongest opponents. According to Public Policy Polling, Romney is slightly ahead among likely Alabama primary voters with 31 percent, compared with 30 for Newt Gingrich and 29 percent for Rick Santorum. In Mississippi, Gingrich leads polling with 33 percent, but Romney is close behind at 31, followed by Santorum with 27 percent.

"There's an increasing perception that Romney has the momentum and that he is going to be the candidate, so I think some people are coalescing behind him because of that," said Hutchings.

How Much Are Gingrich and Santorum Splitting the "Very Conservative Vote"?

On the other hand, Gingrich and Santorum are in a statistical dead heat among Southern voters who consider themselves "very conservative," with Gingrich leading Santorum only 35 percent to 32 percent with them. While Gingrich may draw more of the Tea Party crowd, and evangelicals lean toward Santorum, the two candidates are essentially vying for the same group of voters.

"I don't think people discern too many programmatic or policy differences between Santorum and Gingrich," said Hutchings. "It's more about personality, and perceptions of who's a better debater or has values more like them."

But Hutchings predicts that this split vote won't be enough to block Romney from gaining enough delegates to win the nomination before the convention -- a strategy that his opponents have been counting on by staying in the race. "At this point it's all but a foregone conclusion that Romney's going the get the nomination," he said. "There's some self-deception on the part of the other candidates."

How Much Longer to Go?

"Romney's going to get the nomination, and frankly, anybody who's paying attention knows it," said Hutchings, calling Gingrich's or Santorum's chances of reaching the required 1,144 delegates a near impossibility. "Romney continues to have a lot of resources to fall back on in order to wage campaigns in expensive states, and he has a delegate lead at this stage. In order for him to lose, he would have to not spend a lot of money in the remaining states and, as a consequence, get virtually no support in the remaining states."

That doesn't dampen the high profile of today's races, though. The super-close results still stand to give all of the candidates a boost -- even if for some it's potentially only a boost of a few more weeks. "Part of the appeal of politics for many people is the sporting component: who's going to win, who's up, who's down? Today's primaries play into that," said Hutchings. "But there isn't any drama anymore about who's going to win."

Cynthia Gordy is The Root's Washington reporter.